


Binding

by RoeDusk



Category: Naruto
Genre: Bad Flirting, Betrayal, Emotional Hurt/Comfort, Loyalty, M/M
Language: English
Status: Completed
Published: 2018-02-13
Updated: 2018-02-13
Packaged: 2019-03-17 15:05:40
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 3,153
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13661508
Author URL: https://archiveofourown.org/users/RoeDusk/pseuds/RoeDusk
Summary: Kakuzu fails to assassinate the First Hokage, and ends up fighting his younger brother.Because Kakuzu's praise for intelligent opponents in canon would make Tobirama the perfect rival.





	Binding

He thought he’d understood from the briefing, from the operation and training that followed, just what he was up against. Anyone who required such extremes to fight, to hide his chakra signature and assassinate, must be a monster, a chakra powerhouse with a kekkei genkai of unparalleled power.

But Kakuzu had trained against the ash release of the land of stone, the magma release native to water’s far flung islands, and he knew he could kill this man of plants. Hashirama was an idealist and a fool, albeit one nature had handed a winning hand. With Takigakure’s modified Earth Release in his cells he should be able to come out on top even if the newly appointed Hokage awakened before he could finish the job.

But to face a kekkei genkai user surprise was the most essential tool. That, and having more information than the target. Kakuzu didn’t have all the information. No one had told him the Hokage’s marriage was doing well enough that his new wife slept in the same room. And no one had even hinted at the lengths the younger Senju brother would go to see the elder safe. Even in the middle of allied territory, while both were asleep.

How could they not have known how powerful a sensor he really was?

Kakuzu had slowed his heart down far enough to make using chakra all but impossible, relying on his physical ability to scale the Hokage’s tower. Uchiha thus evaded he eased his way into the building, only to freeze at the sight of brilliant red hair beside the brown he’d been expecting.

Then there was a flare of chakra in the distance, from another room entirely. Tobirama Senju waking from sleep in alarm. Red hair moved, even as brown protested the interruption groggily, and a seal going off threw Kakuzu from the building.

He skid to a stop on the outskirts of the fledgling village, the woods at his back. And that’s when the full chakra signature of the Hokage hit him. In response to Mito’s surge to action Tobirama’s chakra signature flashed to battle readiness, and Hashirama was immediately fully awake.

Then the rest of the village was awake, the Uchiha especially.

And after that, the forest itself, trees swelling to impossible size in an instant, reaching out to ensnare or impale him, driving him further from the village as he dodged.

Kakuzu never stood a chance. Not even just against the God of Shinobi.

When the smoke cleared Mito Uzumaki and her husband stood over the battered, sealed assassin and the forest stood tall enough to blot out the stars. And there in the darkness they spared him, for no other reason than Hashirama’s eventual desire to make peace with Taki.

Mito was no fool, and the burning of the seal in his veins lingered even after she removed it, slowing him down as his chakra tried to repair the damage the Hokage had already caused. But Hashirama himself seemed to honestly believe… Kakuzu wasn’t even sure. That his excuse for letting an assassin go free would make sense to the Uchiha, perhaps.

The shadow that detached from the woods to attack as he retreated made more sense, flickering from disguise into presence all at once in the way of an assassin. Tobirama Senju wasn’t going to just let a threat to his brother’s life escape.

And for the second time in his life Kakuzu found himself completely overwhelmed.

But where Hashirama and Mito were raw power, modified by sense only to varying degrees, Tobirama was calculation and cunning. The perfect counter to his every move and meticulous management of chakra. With the chakra reserves of a normal man he stood toe to toe with giants, and won.

Having nothing to lose but his life, and knowing he would inevitably lose that, Kakuzu found himself stretching his repertoire of jutsu to its limit, determined to delay that inevitable just a little while longer. It was the most alive he’d ever felt, in a fight with no loyalty on the line but to his own life and against an opponent who could outmatch his mind. No one cared if he won, just how badly he lost.

This was his battle to go out on.

“Tobirama!”

Both instinctively dodged away from the wall of wood that erupted from the earth, though the identity of the interloper came easily enough seconds later.

Tobirama frowned down at his clan head. “Brother…”

“Leave him, Tobirama,” Hashirama insisted. “I bear Taki no ill will, nor their assassin. You must let him go.”

“So he can try again?”

“Brother.” Hashirama sighed, and Tobirama twitched. “Consider it an order from your Hokage.”

The younger Senju’s frown deepened, and his gaze flickered to the Uzumaki Heiress. She narrowed her eyes at Kakuzu, but nodded. They would keep watch together.

“Fine,” Tobirama bit out, turning to pin Kakuzu with a glare. “But know that if you ever return, I will end you before you even reach the village.”

“Brother!” Hashirama squaked, “You can’t just threaten people! What if Taki sends him with their delegation?!”

“Then it’s clearly an act of war!” the younger Senju snapped.

Kakuzu hesitated, frowning at the sudden reversal of fortune. But he nodded his understanding before pulling his chakra as close as he could and vanishing towards the border.

It wouldn’t fool the Senju sensor, but perhaps it would at least throw the Uchiha off his trail.

 

* * *

 

 

He’s stopped bleeding, but that’s more a side effect of his Grudge than a representation of damage. Still covered in blood though, even after all these miles, and running just short of exhausting himself with one destination in mind.

(He’d gotten out, gotten vengeance, and yet this was the only next step he could think of. The only one he could stomach making.)

A barely noticeable flare of chakra and he manages to summon an earth shield in time to block the combination Suiton-Raiton jutsu that shoots his way. Tobirama wastes no time on small talk, launching into a string of hand signs that has Kakuzu dodging wide. And then, no matter his intention in coming here, no matter his exhaustion, it’s easy enough to get dragged into the familiar pace of battle.

Only it’s not familiar so much as _right_. A high stakes game of rocks-paper-scissors where no matter what he chooses the other player still gets at least one more win than him. Tobirama must have come from battle himself, or some major sealing work, because he hasn’t been blown away out of hand yet. They’re evenly matched, as much as they ever were, the battle a foregone conclusion even exhausted as they are. A foregone conclusion Kakuzu _came_ for.

But the ending doesn’t come. Laying in the soaked remains of a Suiton jutsu against the tree it had smashed him into, body beaten so bad even the Grudge can’t keep up, chakra depletion making it impossible to reach out, or even move, vision fading. And yet Tobirama just stands there, not making the final move.

Kakuzu snarls.

“You said you’d kill me, you bastard! Damn you, do it!”

“Yes. And yet my brother told me not to.”

There’s so much in those few words, undercurrents that Kakuzu’s mind can’t help but chase even as he’s given up. But more than anything else is pain, and raw loss.

“He’s dead, isn’t he?”

And it hurts to know he’s right, even before Tobirama glares at him. If someone else succeeded where he failed what was it even all for? The betrayal and suffering, the vengeance and years of struggle just to get strong enough to murder his way out. And for what? Someone else had finished what he’d failed to do. Kakuzu wondered if they even cared. If they even knew.

“Who did it?”

“Madara,” Tobirama hissed, the word a curse, and Kakuzu realized he could see blood under the other’s fingers.

“Uchiha Madara? The one he ended the war to found a village with? Bastard.”

A glint of teeth, and Tobirama flexes bloody fingers.

“He will not get far without his lungs. We _will_ find him eventually.”

Which meant it had only _just happened_. And Tobirama had still managed to destroy him in battle immediately afterwards. Kakuzu’s eyes widen involuntarily before he regained control of himself, shaking his head.

“No less than he deserves.”

“Those who betray comrades for doing their jobs deserve no less,” Tobirama mused idly, and Kakuzu flinched. He closed his eyes as the Sensor knelt over him.

“Would you just get on with...”

Fingers traced the tattoos on his arms and he flinched. They burned, lingering phantom pain that he knew he should be rid of. But Tobirama just followed the weak twinges as he tried to pull away.

“Fools,” The Sensor decided after a long moment. “All of them. For throwing you away.”

Kakuzu can’t feel his body well enough to _move_. Can’t _breathe_ he’s gritting his teeth so hard.

“Why do you _care_? I’m an assassin, one who tried to murder your dead brother! Stop toying with me!”

“My brother told me to spare you,” Tobirama replies simply. “It’s a bond that should not exist, but I cannot throw away my brother’s wishes.”

It’s grief, it has to be, a sort of madness seizing the other at having only just lost his brother to an ally then facing down the man who should have been trying to kill him instead. But Kakuzu came here to die, and in search of the scariest opponent he ever faced to make sure he could do it. Now with the adrenaline wearing off he’s tired, and he’s going to do his damndest to get it over with before he has no say anymore.

“Besides,” Tobirama preempts him. “You’re the best fighter I’ve faced in a long time. Konoha could use that strength.”

“You’re crazy,” Kakuzu points out before he can think better of it. Then, “You just fought _Madara_.”

“A madman, but a powerful one,” Tobirama dismissed. “And yet, for all his strength, his cunning leaves much to be desired.” A sideways look. “The most powerful shinobi rely more on brute strength than strategy. They don’t need it, but it is infuriating to know how much they could do if they only _tried_. And those less powerful don’t see it as necessary to match them. It is rare to find a mind that could, yet also _does_.”

“You would trust an assassin at your back?”

“We’re all assassins. Madara was always going to betray the Village, even the Uchiha saw it. My brother was a fool to trust him. But you were loyal, enough that betrayal broke you.”

“And it’s not happening again,” Kakuzu insisted.

“No,” Tobirama agreed darkly, “They’re not.”

  - - - - - - -

It took Kakuzu a few seconds to realize waking up meant he’d finally blacked out. And yet he still wasn’t dead, which was disappointing. But he’d more-or-less expected that, with the mental state Tobirama had been in.

He was not expecting to wake up dry and bandaged, stowed away in a camouflaged tent tucked under the roots of the one of the largest trees he’d ever seen. And he was from Taki.

Senses straining he tried to pinpoint the nearby chakra signature, but couldn’t. Ducking out of the tent was just about as helpful, his still depleted chakra reserves complaining as his battered body spun threads to hold itself together.

To his right there was a flicker of movement, and he turned fast enough to catch a masked ninja disappearing into the forest. Probably a guard, or a babysitter. Kakuzu contemplated following, but decided against it. It didn’t matter in the long run what the guard did, it’s not like the village didn’t already know he was here.

He’d make the most of the extra rest while he could.

  - - - - - - -

It was almost an hour later when a deliberate pulse of chakra advertized Tobirama’s approach. He emerged from the forest flanked by another masked ninja, this one wearing familiar red hair.

If he’d had any thoughts of forcing the other ninja to finish him properly Kakuzu certainly wasn’t going to attempt it with the Hokage’s former wife standing right there as backup. Those odds were hardly fair.

“You appear to have survived.” The Sensor noted instead of a greeting. “Good.”

“Thanks to you, I assume?” Kakuzu shot back with a frown. Tobirama inclined his head in response. As if that made it any better.

The assassin huffed, “A shame.”

“You knew I wouldn’t kill you,” his opponent pointed out mildly.

“At the end maybe,” Kakuzu replied, rolling his eyes as he looked away. “You know I’m not going to join you.”

“True.”

“And you know if you let me go I’m going to go back and finish what I started? They’re all going to die, and no one will be able to stop me.”

“At least learn something before you torch the village,” Tobirama advised, and Kakuzu side eyed him.

“Shouldn’t you be more concerned about this?”

“If I were a better man, maybe. More like my brother. But I’m not.” Tobirama replied. “Not my village, not my problem. And if you happen to find any of them have open bounties, well, Konoha would be happy to cash those in, for a freelancer.”

That earned a full body turn and narrowed eyes.

“You’re serious. How can you be so sure?”

The answering smile was dark.

“Well, it turns out I’ve recently become the Hokage.”

And there’s nothing to say to that. It’s insanity, and something like a lure, Kakuzu doesn’t deign to even look at the offer too closely. It’s definitely a trap somewhere.

“Besides, I’m interested in what that jutsu of yours can do. Learn a bit more about it before you come back to kill me again, would you?”

Kakuzu favors the new Hokage with his most disinterested glare.

Fortunately the guard at Tobirama’s side chooses that moment to intervene.

“That’s it, I need you gone. You’re a terrible influence on each other.”

Kakuzu huffs, turning just slow enough not to miss the flash of the teasing grin that accompanies Tobirama’s response.

“You never let me have nice things.”

As if Kakuzu is something worth keeping.

He scoffs. “Well then, by your leave, _Lord_ Hokage.” He turns to go, away from the cluster of chakra signatures waiting at a distance. He’ll find the border soon enough.

But of course the bastard has to have the last word.

“Granted.”

Insufferable idiot.

  - - - - - - -

He never does go back to Taki.

 

* * *

 

When Tobirama’s consciousness managed to struggle it’s way back from the darkness the first thing he saw was the moon hanging overhead, still in the same phase he’d last seen it but slightly higher in the sky. He wasn’t gone long then.

There was something moving to his left, but he couldn’t turn his head to see yet. And the overpowering scent of blood. He’d been stabbed, but he couldn’t feel it. That wasn’t good.

He wondered if the children had made it out.

Even burned out past chakra exhaustion his senses wouldn’t turn off, and all they could feel around him were sputters - dying throes of multiple Shinobi - and one steady flame. The one to his left, actually, spinning tendrils that snaked out over his own dimming embers.

A powdered chakra pill was forced into his mouth, slowly dissolving in the blood on his tongue. He couldn’t move to chew, or even swallow, but some could be absorbed into his bloodstream from there. Not a bad plan. He was apparently being rescued.

“You’re lucky these fools had such a high bounty,” his rescuer growled. And _there_ was the pain, slowly fading in as the tear in his chest pulled itself back into alignment. “And that they barely nicked your heart. How does a ninja miss that badly anyway? Amateurs.”

“To be fair,” Tobirama breathed, smiling faintly when his jaw actually obeyed, “I dodged.”

“You dodged,” the other ninja huffed. “If you dodged, how are you this beat up?”

“And not everyone can microadjust internally the way you can,” Tobirama continued as if he hadn’t spoken.

“Obviously,” Kakuzu scoffed. “Now be quiet. I’ve never actually tried putting someone back together with this before.”

It’s remarkably quiet for a battlefield. But it’s Kakuzu, the most feared mercenary in the Shinobi Nations. Tobirama decides the children probably made it out, because Kakuzu killed everyone who might have managed to go after them. So he forces himself to relax, entertaining himself by trying to identify what each flash of pain is before the strands of the missing-nin’s jutsu manage to realign the wound. He’s never been bisected quite this far before, it’s good research for some of the self-healing jutsus he’s been considering.

Minutes pass, and the last of the chakra signatures around them flicker out. Kakuzu frowns down at him as he continues his work, cautious but fast enough to prevent as much of the blood loss as he can. Tobirama feels lightheaded, but thinks he might even survive.

Mito’s going to have his head for this.

“I’ve been following your work,” he says finally, breaking the silence.

“That’s nice,” Kakuzu replies, deadpan. “Now shut up.”

“You never come to Konoha to turn any of your bounties in.”

 _That_ gets him a glare.

“Of course not. I don’t need your help to survive.”

“No, you don’t,” Tobirama agrees happily.

Kakuzu is giving him a strange look now, a mix of understanding and disbelief. Tobirama wants to point at it as proof, but Mito isn’t there to see. She insists falling for someone isn’t like fighting them, but she married Hashirama so he’s pretty sure she’s lying.

Hashirama would have understood what he meant.

“I have students now,” Tobirama offers into the silence, and Kakuzu’s eyebrows go up.

“Oh really? Well then, you’re doing a great job.” He turns back to focus on what he’s doing, only to stop as Tobirama continues.

“You should meet them.”

There’s a beat of silence, then Kakuzu sighs.

“You really are an idiot. I’m certainly not coming to Konoha to meet your brats.” The last of the stitchest ties off and he pulls back. “If I come at all it’s to make sure my efforts haven’t been wasted.”

Tobirama’s grinning at him now, and the other shinobi is quick to correct himself.

“I’m only heading that way to turn in the bounty on the Kinkaku Force. I don’t want to have to carry them all across the whole of Fire Country to find a bounty broker. Konoha is closer. Especially if I have to carry you part of the way too.”

“Ah, that’s right, I won’t fit in a capture scroll.”

“Those only work on the dead, idiot.”

“Actually, I’m working on modifying a summoning contract to…”

“Don’t you ever shut up?”

Mito is going to murder him. Kakuzu might even help, but Tobirama doesn’t care that much.

**Author's Note:**

> Written in one day, because there was a rabid plot bunny that wouldn't leave me alone until I got rid of it.
> 
> Inspired, at least partly, by [blackkat](http://archiveofourown.org/users/blackkat) discussing the Kakuzu/Hashirama pairing on their [tumblr](http://blackkatmagic.tumblr.com/). I tried to picture it and got this instead. 
> 
> Thank you for everyone who's already seen this on tumblr, your reblogs, likes, and excited tagging made my evening. I hope you enjoy the edited version as well!


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